1. Field of the invention
This invention relates to image creating apparatuses and image display apparatuses. More particularly, this invention relates to an image creating apparatus and image display apparatus for generating and/or displaying image data approximated for representing realistic three-dimensional images, particularly when the images are displayed using polygon representation.
2. Description of the Prior Art
In conventional games of three-dimensional representation (3D), images of background objects and moving objects are merely displayed through three-dimensional image data involving three-dimensional coordinate data and textures (patterns and material feelings including colors) as if the images were photographed in a predetermined direction by a camera located at a predetermined distance.
Meanwhile, conventional games of two-dimensional representation can display images, in combination, of the background object (or background character or background picture) and the moving object (moving character or game hero character, etc.). However, the relation in position between the background object and the moving object is determined only either one of at the front or the rear of the background object with reference to the moving object. It is therefore impossible to display the background objects depicted between a plurality of background objects (e.g. between a house and a mountain or between a car and a building, or the like) in one background scene by merely setting the backward-forward relation for each background object. To this end, the conventional background image is nothing more than a mere planar image with no depth data, so that the moving object (e.g. hero character) thus depicted, upon passing between a plurality of other background objects, cannot be represented as if it passed behind or in front of or between the objects in away of perspective representation with depth given for the objects.
FIG. 1 is a view showing an on-screen space for displaying background objects and a moving object due to a conventional technique. The example of FIG. 1 shows a case that, when rendering a person as a moving object 1 and depicting a building 2 and a tree 3 as background objects, the moving object 1 is represented in preference to the background objects. That is, the moving object 1 is set at a higher order of priority than the background objects 2 and 3. In this case, the moving object 1 is displayed as if it existed in front of the building 2 during movement from a position (a) to a position (b) and from the position (b) to the position (c), whereas it is represented at the front of the tree 3 during movement from a position (c) to a position (d). The moving object 1 in movement from the position (d) to a position (e) is displayed (solely) without superposition over the background.
FIG. 2 is a view showing an on-screen space for displaying background objects and a moving object due to the conventional technique. In an example of FIG. 2, a person is depicted as a moving object 1 and a building 2 and a tree 3 are drawn as background objects, wherein the moving body 1 is set in lower priority than the background objects 2 and 3. In this case, when the moving object 1 in movement from a position (a) to a position (b) comes to a position that is overlapped with the building 2, no representation is made for the portion overlapped with the building 2, thereby displaying the person as if he was behind the building. During movement from the position (b) to a position (d), display is similarly done. Thereafter, when the moving object 1 passes past an left end of the building 2 and further moves from the position (d) to a position (e), it is solely displayed because of the absence of the building 2 or the tree 3 there.
In the conventional art, when the moving object 1 becomes overlapped with the background object 2 or 3, nothing is done more than display only with either one of the moving object 1 or the background object 2 and 3 which is higher in priority order. This is because the data defining the depth (depth data) is not assigned to each of the background objects and the moving object.
Where a three-dimensional image is displayed on a display depending upon three-dimensional data (or polygon data; i.e. coordinate data at polygon corners X, Y, Z) for representing an object (including background objects and/or moving objects; background characters, also referred to as moving characters) constituted by gathering of a plurality of polygons, there is a necessity of representing a greater number of polygons in order to display an image with higher reality and precision. However, it takes long time for computation, as the number of polygons increases greater. There often encountered is a case where the computation for representing one frame of a three-dimensional image becomes impossible for one frame (or during vertical blanking), resulting in overburdening of processing. The resulting display image might be unnatural of movement just like frame-basis feeding. Thus, there has been a difficulty of smoothly changing in real time the three-dimensional image.
On the other hand, where the background object is displayed by combining with a moving object (hero character), there has been no setting in the forward-backward relation between the background object depicted in the background scene and the moving object. As a result, the forward-backward relation as to the background object and the moving object can not be met with the actual movement.
It is therefore an object of the present invention to provide an image creating apparatus which is capable of creating images utilizable for three-dimensional display with reality by providing depth data to each dot constituting for pixels (picture elements) for background objects being displayed on a display, when background objects are displayed depending upon three-dimensional data for representing the object constituted by of a plurality of polygons.
It is another object of the present invention to provide an image creating apparatus which is capable of creating images utilizable for realistic three-dimensional display by providing depth data to each dot constituting for background objects and pixels being displayed on a display when the background object and the moving object are synthetically displayed depending upon three-dimensional data for representing the object constituted by a plurality of polygons.
It is further object of the present invention to provide an image display apparatus effective for realistic three-dimensional display by providing depth data to each dot constituting for pixels for background objects to be displayed on a display where background objects are displayed based on three-dimensional data for representing the object constituted by a plurality of polygons.
It is still another object of the present invention to provide an image creating apparatus and/or an image display apparatus that are free from overburdening or overloading on the CPU even where there are a number of objects existing in the three-dimensional space for being displayed.
An image crating apparatus according to the present invention is adapted to create an image constituted by gathering of dots for a plurality of scenes visually perceived as viewed in three-dimensional different two or more directions from a certain view point existing in a three-dimensional space, the apparatus comprising: a polygon image data generating means for generating polygon image data constituted by three-dimensional data and texture data so as to represent, for each polygon, an object existing in the three-dimensional space by a plurality of polygons; a color data storing means having a storing capacity corresponding to the number of the dots for a plurality of background scenes, to temporarily store color data on each background scene on a dot-by-dot basis; a depth data storing means having a storing capacity corresponding to the number of the dots for the plurality of the background scenes, to temporarily store depth data on the background scene on a dot-by-dot basis; a color data writing means for converting into dot image data the polygon image data obtained upon being directed in different two or more directions in the three-dimensional space at the certain view point, to write the color data on the dot-by-dot basis into a corresponding storing position of the color data storing means depending upon the texture data of the polygon; and a depth data writing means for determining, by computation, the depth data on the dot depending upon the three-dimensional coordinate data of the polygon when converting into the dot image data the polygon image data obtained upon being directed in the different two or more directions in the three-dimensional space at the certain view point, to write the depth data on the dot-by-dot basis into a corresponding storing position of the color data storing means.
The color data storing means and the depth data storing means respectively have storing capacities for storing, on the dot-by-dot basis, the color data and the depth data of the object existing in the background scene obtained by dividing a 360-degree range through parallel rotation about the view point, the color data writing means writing, on the dot-by-dot basis, the color data on the object existing in the divided background scene into a corresponding storing position of the color data storing means to the background scene, and the depth data writing means writing, on the dot-by-dot basis, the depth data on the object existing in the divided background scene into a corresponding storing position of the depth data storing means to the background scene.
The color data storing means and the depth data storing means respectively have storing areas of six faces for the background scenes, and the color data writing means and the depth data writing means respectively writing the color data and the depth data into a corresponding face of the six faces, on the left, right, front, rear, upper and lower, as viewed from the view point, in the color data storing means and the depth data storing means at a storing position corresponding to the dot of the object.
The polygon image data generating means includes a first polygon image data generating means for generating background polygon image data constituted by three-dimensional coordinate data and texture data on the polygon for the background object in order to represent by the plurality of the polygons the background object existing in the three-dimensional space, a second polygon image data generating means for generating moving polygon image data constituted by three-dimensional coordinate data and texture data on the polygon for the moving object to be displayed in order to synthesize the moving object with the background polygon image generated by the first polygon image data generating means and represent the moving object by the plurality of the polygons, wherein the color data writing means converts the background polygon image data for the background object generated by the first polygon image data generating means into dot image data for the background object, and the polygon image data for the moving object generated by the second polygon image data generating means into dot image data for the moving object, and writes color data on one of the background object and the moving object which is closer to the view point into the corresponding storing position of the color data storing means depending upon the respective depth data of the background polygon and the moving object polygon, and the depth data writing means writing the depth data of the one of the background object and the moving object which is closer to the view point into the storing position corresponding to the depth data depending upon the depth data of the background object polygon and the moving object polygon when the color data writing means writes the color data of the background object polygon and the moving object polygon into the corresponding storing position of the color data storing means.
An image display apparatus according to the present invention is adapted to display on a raster scan display means the image, and further comprises a reading means for reading the color data written in the color data storing means in synchronism with raster scanning over the raster scan display.
According to the present invention, various objects, such as background objects and/or moving objects depicted by polygons, can be represented by a variety of combinations of overlapping manners in the three-dimensional space where the background objects and/or the moving objects are present, thus realizing realistic image representation.
According to the embodiments of the present invention, visual effects are exhibited in a manner just like the processing, in real time, of all the polygons in the three-dimensional space. Moreover, if the polygons for a multiplicity of objects to be displayed by a plurality of background scenes around the camera position are converted beforehand into the color data on a dot-by-dot basis, there is obtained an advantage that the processing is possible without lowering the capability of image processing, even if the number of objects to be represented by polygons is considerably increased.
Furthermore, even where the moving object is displayed by the combination with the background scene, since the representation is possible for the forward-backward relations to the background object depicted in the background scene and the moving object, there is further provided and an advantage that the representation of the moving object can be displayed as if it was entering into a picture book to move around therein.
In addition, since the background scene is provided with depth data for each dot, it is possible to designate the forward-backward relation to the dots between the background scene and the moving object, offering an advantage of more realistic three-dimensional image representation.
The above described objects and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.